2. Field of the Invention
The present invention relates to a safety-shield system for a syringe and, more particularly, for a single use flexible-type compression syringe. The present invention also relates to an injection device with such a safety shield system.
3. Description of the Related Art
A “compression syringe”, as used herein means a” syringe which hold medicament in a reservoir defined walls with at least one being compressible and when squeezed by a user's hand, causes the medicament to be expelled out from the reservoir and administered to a patient through a needle cannula connected to the reservoir. Compression syringes are prefilled with a single dose of the medicament which is completely delivered upon compressing the reservoir. Because of their lightweight and compact properties, their ruggedness and low cost, compression syringes are favored in many circumstances.
A known compression syringe assembly is depicted in FIGS. 1 and 2 and is described in U.S. Pat. No. 4,955,871. The compression syringe 10 includes a reservoir 46 which is configured to be rendered unusable upon discharge of a full dose of medicament. To operate the compression syringe 10, a protector cap 30 must be removed to expose a needle cannula 12 connected to the reservoir 46. To avoid contamination from the used compression syringe 10, the needle cannula 12 must be covered after use. For the compression syringe 10 shown in FIGS. 1 and 2, this is accomplished by re-capping the needle cannula 12 with the protector cap 30. However, this task may cause the compression syringe 10 users, such as health care professionals to accidentally stick themselves while replacing the cap 30. Accordingly, there is a need for a safety shield system that can cover an exposed needle cannula tip of a compression syringe after use to prevent exposure to the used needle cannula tip.